How to Install just on Ubuntu: A Handy Command Runner for Your Projects

just is a lightweight command runner for the commands you keep re-typing on every project: build, test, lint, deploy, seed the database, tail the logs. You record them as recipes in a justfile and then invoke them by name with just <recipe>. It deliberately looks like make so the syntax feels familiar, but it strips out the build-system machinery that makes Makefiles awkward for plain task running.

The payoff is that each repository gains a small, self-documenting catalogue of commands. Anyone can run just --list to discover what a project supports, and the whole team ends up running identical commands rather than slightly different ad-hoc scripts.

Ubuntu does not carry just in its default archives, and compiling it means installing the Rust toolchain. The unofficial deb.griffo.io repository removes that friction by offering a current prebuilt package installable with apt.

What Makes just Special?

  • 📝 Readable recipes - Named recipes in a plain justfile that reads like a task list.
  • 🔧 A runner, not a builder - Focused on executing commands, without make’s incremental-build surprises.
  • 🔤 Arguments and defaults - Recipes take positional parameters, defaults, and variadic arguments.
  • 🌐 Portable - Works on Ubuntu, macOS, and Windows and can call any interpreter.
  • 📋 Discoverable - just --list shows every recipe and its documentation comment.
  • 🧬 Variables and helpers - Interpolation, environment access, and string functions built in.
  • 📂 Polyglot recipes - Write a recipe body in Python, Node, Ruby, or any shebang language.
  • ⚡ Single fast binary - Compiled in Rust with no runtime dependencies.

Why Use the deb.griffo.io Repository?

  • Simple installs and upgrades through APT, exactly like any other Ubuntu package.
  • Automatic dependency management provided by the packaging.
  • Tracks upstream releases closely, so new just versions arrive promptly.
  • No source builds and no Rust toolchain to maintain.
  • Supports current Ubuntu releases (Jammy, Noble, and newer).

Prerequisites

Make sure the following are in place first:

  • An Ubuntu system (Jammy 22.04 LTS, Noble 24.04 LTS, or newer)
  • sudo privileges
  • curl installed (sudo apt install curl if needed)

Step 1: Add the deb.griffo.io Repository

Register the key and repository with APT:

# Create the keyrings directory
sudo install -d -m 0755 /etc/apt/keyrings

# Download and install the repository GPG key
curl -fsSL https://deb.griffo.io/EA0F721D231FDD3A0A17B9AC7808B4DD62C41256.asc | sudo gpg --dearmor --yes -o /etc/apt/keyrings/deb.griffo.io.gpg

# Add the repository (auto-detects your distro codename)
echo "deb [signed-by=/etc/apt/keyrings/deb.griffo.io.gpg] https://deb.griffo.io/apt $(lsb_release -sc 2>/dev/null) main" | sudo tee /etc/apt/sources.list.d/deb.griffo.io.list > /dev/null

# Update the package list
sudo apt update

Step by step:

  1. Creates /etc/apt/keyrings with sensible permissions for repository keys.
  2. Downloads and de-armours the GPG key so APT can verify package signatures.
  3. Adds the sources entry bound to that key, auto-detecting your Ubuntu codename.
  4. Updates the package index so APT knows about the new packages.

Step 2: Update the Package List

If you skipped the final command above, run it now:

sudo apt update

Step 3: Install just

Install with APT:

sudo apt install just

APT downloads the latest packaged just and resolves any dependencies.

Step 4: Verify the Installation

Confirm the install by printing the version:

just --version

Expect output similar to:

just 1.34.0

Getting Started with just

Writing a justfile

Create a file called justfile at the top of your project. Each recipe is a name followed by indented commands:

# List available recipes when run with no arguments
default:
    @just --list

# Install dependencies
setup:
    npm install

# Run the dev server
dev:
    npm run dev

# Run tests
test:
    npm test

Run any recipe by name from anywhere inside the project:

just setup
just dev

Running just alone executes the first recipe, and just --list prints the full menu with descriptions.

Passing Arguments

Recipes take parameters, and parameters can have defaults:

# Tag a release, defaulting to patch
release level="patch":
    npm version {{level}}

# Run a single test file
test-file file:
    npx vitest run {{file}}

Invoke them with positional arguments:

just release minor
just test-file src/app.test.ts

Variables and dotenv

Declare variables and toggle settings at the top of the file:

# Load variables from a .env file
set dotenv-load

registry := "ghcr.io/acme"

publish:
    docker push {{registry}}/app:latest

set dotenv-load pulls values from a local .env, and {{registry}} interpolates the variable into the command.

Recipes in Any Language

Thanks to shebang support, a recipe can be written in a different interpreter entirely:

# A Node recipe embedded in the justfile
report:
    #!/usr/bin/env node
    const pkg = require("./package.json");
    console.log(`${pkg.name} v${pkg.version}`);

Useful Flags

These flags help in everyday use:

just --list                 # show every recipe
just --show dev             # print a recipe's source
just --choose               # pick a recipe interactively (pairs with fzf)
just --set registry local   # override a variable at runtime

Keeping just Updated

Since just comes from the repository, it updates with the rest of the system:

sudo apt update && sudo apt upgrade

Other Tools from deb.griffo.io

The repository ships several tools that slot neatly into a project workflow:

  • fzf - A fuzzy finder that backs just --choose for interactive selection.
  • lazygit - A terminal UI for Git alongside your recipes.
  • zoxide - A smarter cd for hopping between projects.
  • zellij - A multiplexer for running tasks side by side.

Troubleshooting

GPG or Key Errors

If APT reports the repository is not signed, re-import the key:

sudo rm -f /etc/apt/keyrings/deb.griffo.io.gpg
curl -fsSL https://deb.griffo.io/EA0F721D231FDD3A0A17B9AC7808B4DD62C41256.asc | sudo gpg --dearmor --yes -o /etc/apt/keyrings/deb.griffo.io.gpg
sudo apt update

Package Not Found

If APT cannot locate the just package:

  1. Re-run sudo apt update to refresh the index.
  2. Verify your Ubuntu release is supported (Jammy, Noble, or newer).
  3. Check the sources entry:
cat /etc/apt/sources.list.d/deb.griffo.io.list

just Cannot Find a justfile

just searches the current directory and every parent for a file named justfile or .justfile (case-insensitive). If it reports none found, confirm your location or point at one explicitly:

ls -la justfile
just --justfile ./ops/justfile deploy

Uninstalling

To remove just:

sudo apt remove just

To also remove the repository:

sudo rm -f /etc/apt/sources.list.d/deb.griffo.io.list
sudo rm -f /etc/apt/keyrings/deb.griffo.io.gpg
sudo apt update

Conclusion

just replaces scattered helper scripts and forgotten one-liners with a single, discoverable command menu per project, and it keeps everyone on the team running the same tasks the same way. On Ubuntu, installing it from deb.griffo.io gives you a current build that upgrades cleanly with apt upgrade.

Write a justfile once, and your project’s common commands are always just a just away.

Resources

Disclaimer: The deb.griffo.io repository is an unofficial community project and is not affiliated with the official Debian or Ubuntu projects, or with the upstream just project.